Surface plasmon enhanced absorption and suppressed transmission in periodic arrays of graphene ribbons

TL;DR

This paper theoretically investigates how periodic arrays of graphene ribbons can enhance absorption and suppress transmission through resonance diffraction, revealing complex plasmonic behaviors influenced by carrier relaxation times.

Contribution

It provides a systematic theoretical analysis of resonance diffraction in graphene ribbon arrays, highlighting the impact of carrier relaxation times on resonance richness and transmission suppression.

Findings

Higher relaxation times lead to more resonances and complete transmission suppression.

Resonant features are linked to leaky plasmonic modes.

The longest-wavelength resonance shows the highest transmission dip and significant spectral shifts.

Abstract

Resonance diffraction in the periodic array of graphene micro-ribbons is theoretically studied following a recent experiment [L. Ju et al, Nature Nanotech. 6, 630 (2011)]. Systematic studies over a wide range of parameters are presented. It is shown that a much richer resonant picture would be observable for higher relaxation times of charge carriers: more resonances appear and transmission can be totally suppressed. The comparison with the absorption cross-section of a single ribbon shows that the resonant features of the periodic array are associated with leaky plasmonic modes. The longest-wavelength resonance provides the highest visibility of the transmission dip and has the strongest spectral shift and broadening with respect to the single-ribbon resonance, due to collective effects.